how to get the previous task name in Perl in ipl file?

Hi,

I have a requirement where in i need to check the condition at current task of the workflow if the name of the previous task matches to the name that is assigned for in wft (ipl) file. However i am not sure how to get the previous task name to write a new code for present task.

Can you help me providing some guidance with the sample code snippet on how should we get the name of the previous task in perl code in wft file.

Let me know if any further information is required from me.

Sita

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Comments

Adam Stoller

Use the wfvarstartop (or wfvarfinishop) elements in your [preceeding] tasks to set a job variable to the name of the task and have your script retrieve that information and do "the right thing".

Rick Poulin

FYI -- if instead you write your new task in Java, you can get the workflow events in chronological order from the CSWorkflow object and figure it out from there. This approach would be slightly more robust just because it would potentially make it easier to reorganize your workflow later if needed.

However, this API is not available in the perl objects, so ghoti's suggestion is the only option if you must stick with perl.

mgammon

sub get_prior_wftask {
	my ($taskid) = @_;

	my $task = new TeamSite::WFtask( $taskid );
	my $wf = new TeamSite::WFworkflow( $task->GetWorkflowId() ); 

	# unactivated tasks will return '0' for $_->GetActivationTime()
	my @sorted_tasks = sort { $b->GetActivationTime() <=> $a->GetActivationTime() } @{$wf->GetTasks()};

	# iterate activation time descending looking for last task to return
	my $match = 0;
	foreach my $task ( @sorted_tasks ) {
		# check for current taskid
		if ( $task->GetId() == $taskid ) {
			$match++;
			next;
		}
		# skip if task is unactivated
		next if ( $task->GetActivationTime() == 0 );
		# skip if we've not yet seen current taskid
		next unless ( $match );
		# this should be task immediately preceding current
		return $task;
	}	

	return;
}

Above will return task that was in an activation state immediately preceeding the task defined by $taskid. You might have issues if two previous tasks complete in same second.

Rick Poulin

OP, be aware that @mgammon 's code sample works by returning the "most recently active" task. This code assumes that the workflow is sequential and doesn't have any concurrent branches. It's a quick solution that might be ok for some use cases, but the thought of someone coming in and adding a fork in the workflow while being unaware of this limitation makes me personally uneasy. There's nothing explicitly wrong with this approach, just make sure you understand it and document it properly for the next guy.

mgammon

As pointed out by @rpoulin, you should take my note below the code literally. The function will, in fact, only return the task that was in an activation state immediately preceding the task identified by $taskid argument.